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skills/billing-automation/SKILL.md

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+---
+name: billing-automation
+description: Build automated billing systems for recurring payments, invoicing, subscription lifecycle, and dunning management. Use when implementing subscription billing, automating invoicing, or managing recurring payment systems.
+---
+
+# Billing Automation
+
+Master automated billing systems including recurring billing, invoice generation, dunning management, proration, and tax calculation.
+
+## Use this skill when
+
+- Implementing SaaS subscription billing
+- Automating invoice generation and delivery
+- Managing failed payment recovery (dunning)
+- Calculating prorated charges for plan changes
+- Handling sales tax, VAT, and GST
+- Processing usage-based billing
+- Managing billing cycles and renewals
+
+## Do not use this skill when
+
+- You only need a one-off invoice or manual billing
+- The task is unrelated to billing or subscriptions
+- You cannot change pricing, plans, or billing flows
+
+## Instructions
+
+- Define plans, pricing, billing intervals, and proration rules.
+- Map subscription lifecycle states and renewal/cancellation behavior.
+- Implement invoicing, payments, retries, and dunning workflows.
+- Model taxes and compliance requirements per region.
+- Validate with sandbox payments and reconcile ledger outputs.
+- If detailed templates are required, open `resources/implementation-playbook.md`.
+
+## Safety
+
+- Do not charge real customers in testing environments.
+- Verify tax handling and compliance obligations before production rollout.
+
+## Resources
+
+- `resources/implementation-playbook.md` for detailed patterns, checklists, and examples.